Echocardiographic observations are described in 25 opiate addicts with active infective endocarditis (IE) involving apparently previously normal valves. BIBLIOGRAPHIC REFERENCES: Andy, J.J., Sheikh, M.U., Ali, N., Barnes, B.O., Fox, L.M., Curry, C.L., and Roberts, W.C.: Echocardiographic Observations in Opiate Addicts with Active Infective Endocarditis. Frequency of involvement of the various valves and comparison of echocardiographic features of right and left-sided cardiac valve endocarditis. American Journal of Cardiology 40:17-23, July 1977.